JP2010030501A - Automobile hood panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automobile hood panel made of fiber-reinforced plastic which is capable of the weight reduction as an original purpose, and reliably achieving the absorption of impact energy and superior in the performance for protecting the head of a pedestrian. <P>SOLUTION: The automobile hood panel comprises an outer panel made of fiber-reinforced plastic forming an outer surface, and an inner panel made of fiber-reinforced plastic joined with the outer panel. The inner panel has an adhesive part to the outer panel, and a part of the adhesive part is a low-strength adhesive part having the adhesive strength lower than that of other adhesive part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automotive hood panel made of fiber reinforced plastic (FRP). More specifically, the present invention has a light weight and high rigidity, and in particular, effectively absorbs an impact load at the time of collision with a pedestrian, and walks. The present invention relates to an automobile food panel made of fiber reinforced plastic that can protect a person from impact.

  Automobiles are required to improve safety in the event of a collision, and in addition to ensuring the safety of passengers in the event of a collision with a pedestrian, it is also required to ensure the safety of pedestrians.

  In the event of a collision between a pedestrian and a car, the pedestrian receives an impact load on the head and legs. In particular, because damage to the head increases the risk of pedestrian death or serious injury, the hood's hood panel, which is likely to collide with the pedestrian's head, has high shock absorption during pedestrian collision. It is required to have a structure that suppresses the impact on pedestrians.

  For this reason, the automobile hood panel is designed to be deformed to absorb the collision energy and mitigate the impact in the event of a collision. At that time, if the hood panel comes into contact with the body structure under the hood panel or a rigid object such as an engine, the hood panel is prevented from being deformed at that time, resulting in significant damage to the pedestrian's head. End up.

  As a reference for evaluating the safety of a pedestrian's head impact (pedestrian head protection standard), the acceleration received when the head collides with the hood panel and the collision time as shown in Expression (1) The calculated head injury value (HIC value) is introduced, and it is required to keep the HIC value below a predetermined value. In particular, when the HIC value is 1000 or less, the pedestrian survival probability at the time of a pedestrian collision is extremely high.

... Formula (1)

In the formula, a is a triaxial combined acceleration at the center of gravity of the head, t1 and t2 are times when the HIC value is maximum at a time when 0 <t1 <t2, and an action time (t2−t1) is 15 msec. It is decided as follows.

  On the other hand, metal food panels such as aluminum and steel have been conventionally used as automobile food panels. In these metal hood panels, in order to satisfy the pedestrian head protection standards, a plurality of cone-shaped reinforcing members are arranged between the outer panel and the inner panel, and these reinforcing members are deformed to absorb collision energy. A structure that can be made (for example, Patent Document 1), a structure in which an upspoiler is added to the hood panel on the hood panel in order to secure a large moving distance (stroke) of the head (for example, Patent Document 2), etc. Has been proposed.

  However, the addition of parts for pedestrian head protection measures, such as reinforcing members and appaspoilers, causes a problem of designability, and it is necessary to arrange a plurality of parts. There are problems such as an increase in the hood panel assembly process accompanying an increase in the number of parts and a deterioration in quality due to the process increase.

  On the other hand, in recent years, instead of metal hood panels, fiber reinforced plastic hood panels have been actively developed for the first purpose of weight reduction. This is because the fiber-reinforced plastic is larger than other materials such as metal in terms of specific rigidity and specific strength, so that a lightweight and high rigidity / high strength product can be obtained.

  Furthermore, fiber reinforced plastics can be combined with fibers, resins, fiber orientations, and the like according to the required performance, and can be designed with a higher degree of freedom than metal hood panels.

  For this reason, most of them have a simple shape (for example, Patent Document 3) in which an outer panel made of fiber reinforced plastic that forms the outer surface and an inner panel made of frame-like fiber reinforced plastic that extends over the periphery of the outer panel are joined. is there.

  However, regarding the pedestrian head protection performance, in the case of a fiber reinforced plastic hood panel having such a frame-like inner panel, the layout of the inner panel in the metal hood panel is different. The technology developed in the food panel cannot be easily applied as it is.

  In addition, the hood panel made of fiber reinforced plastic is deformed while maintaining the shape of the entire hood panel because of its high rigidity, so that the hood panel is in contact with a rigid body such as a vehicle structure or an engine below the hood panel. Sometimes, impact energy absorption is abruptly hindered and damage to pedestrians increases.

  Thus, some structures have been proposed for improving the pedestrian head protection performance even in the fiber reinforced plastic hood panel (for example, Patent Document 4). However, it is not always sufficient to consider the weight reduction that is the first purpose.

Thus, there has been no proposal of a fiber reinforced plastic food panel that achieves both weight reduction and pedestrian head protection performance.
JP 2003-226264 A JP-A-2005-53418 JP 2002-284038 A JP 2005-212255 A

  The present invention solves the above-mentioned problems of the prior art, enables the weight reduction which is the original purpose in the fiber reinforced plastic automobile hood panel, and has excellent pedestrian head protection performance. An object of the present invention is to provide an automotive hood panel that can reliably achieve impact energy absorption.

In order to achieve the above object, the automobile hood panel of the present invention has one of the following configurations. That is,
(1) An automotive hood panel comprising an outer panel made of fiber reinforced plastic forming an outer surface and an inner panel made of fiber reinforced plastic joined to the outer panel, the inner panel being the outer panel A vehicle food panel characterized in that a part of the adhesive part is a low-strength adhesive part having a lower adhesive strength than that of other adhesive parts.
(2) The automobile food panel according to (1), wherein the low-strength adhesive portion is formed by changing an application thickness of the adhesive.
(3) The automobile food panel according to (1) or (2), wherein the low-strength adhesive portion is formed by providing a step or / and an inclination in the adhesive portion.
(4) The automobile food panel according to any one of (1) to (3), wherein the low-strength adhesive portion is formed by changing an adhesive application area of the adhesive portion.
(5) The said low-strength adhesion part is a food panel for motor vehicles in any one of (1)-(4) formed by changing the kind of adhesive agent.
(6) The automobile hood panel according to any one of (1) to (5), wherein a surface treatment is applied to the bonded portion of the inner panel and / or the bonded surface of the outer panel to which the bonded portion is bonded.
(7) The automobile food panel according to any one of (1) to (6), wherein at least some of the reinforcing fibers used in the fiber-reinforced plastic are carbon fibers.

  According to the present invention, a low-strength adhesive portion that allows the inner panel to be peeled directly from the outer panel is provided on the adhesive portion of the fiber-reinforced plastic inner panel without providing a reinforcing member between the inner panel and the outer panel. By providing, it becomes possible to reliably achieve the absorption of impact energy when colliding with a pedestrian and to have excellent pedestrian head protection performance. Furthermore, since a reinforcing member is not used, it is possible to satisfy the weight reduction which is the original purpose of a fiber reinforced plastic automobile food panel.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the drawings. Note that the illustrated embodiment is merely an example, and is not limited in the following description.

  1 is a plan view of an automotive hood panel according to an embodiment of the present invention as viewed from the engine side, FIG. 2 is an exploded view of the hood panel shown in FIG. 1, and FIG. 3 is an arrow AA in FIG. FIG. 1 to 3, 1 is a hood panel, 2 is an outer panel, 3 is an inner panel, and these outer panel 2 and inner panel 3 are made of fiber reinforced plastic, and are bonded to each other with an adhesive 6. A hood panel 1 is configured as the entire joined body. The hood panel 1 is mounted in front of the vehicle (see FIG. 10) and covers the engine room and the like.

  The outer panel 2 is a member that forms the outer surface, and constitutes the appearance of the vehicle when attached to the vehicle.

  The inner panel 3 is disposed on the engine room side, and has a function as a stiffener that reinforces a lack of rigidity of the outer panel 2. The inner panel 3 is provided with a hood lock striker 4 attached to the front center of the vehicle body constituting the opening / closing mechanism for opening and closing the hood panel 1 and hinges 5 attached to both rear ends of the vehicle body. The hood panel 1 is attached to the vehicle.

  An adhesive portion 7 for adhering to the outer panel 2 is provided on the peripheral edge portion of the inner panel 3. As shown in FIG. 2, when the inner panel 3 has an opening at a substantially central portion, the bonding portion 7 is also provided at the peripheral portion of the opening. In the present invention, it is necessary for at least a part of the bonding portion 7 provided in this way to be a low-strength bonding portion 8 having a low bonding strength.

  As an example, as shown in FIG. 3, an adhesive portion 7 and a low-strength adhesive portion 8 with the outer panel 2 are provided at both ends of the cross section in the axle direction at the front edge portion of the inner panel 3. In addition, it has the structure which undulated in uneven | corrugated shape between both adhesion parts according to required rigidity.

  As shown in FIG. 6, when the pedestrian's head 10 collides with the hood panel 1, the hood panel 1 is rapidly recessed toward the inside of the vehicle body. When the hood panel 1 is recessed until the inner panel 3 collides with the rigid part 9 such as the engine, the adhesive 11 applied to the low-strength adhesive portion 8 is peeled off as shown in FIG. 7, and the outer panel 2 and the inner panel 3 are peeled off. The joint is partially released.

  Next, an effect obtained by providing the low strength adhesive portion 8 on the inner panel 3 will be described.

  FIG. 4 is a representative diagram showing the relationship between the elapsed time from the collision and the acceleration generated on the pedestrian's head 10 when the pedestrian's head 10 collides with the hood panel 1. In FIG. 4, the solid line shows the acceleration diagram G1 of the fiber reinforced plastic hood panel, and the dotted line shows the metal hood panel acceleration diagram G2.

  When the pedestrian's head 10 collides with the hood panel 1, two peaks occur in the acceleration history as shown in FIG. The first peak (first peak) is an acceleration that occurs when the pedestrian's head 10 collides with the hood panel 1 (primary collision), and occurs between about 5 msec from the start of the collision. Due to this collision, the entire hood panel 1 starts to be deformed, and the acceleration generated in the pedestrian's head 10 is moderated to some extent by the behavior. The second peak (second peak) is an acceleration generated by the hood panel 1 deforming and sinking after the first peak and further colliding with the rigid part 9 such as an engine (secondary collision), This occurs after approximately 5 msec from the start of the collision.

  Thus, when the pedestrian's head 10 collides with the hood panel 1, in addition to the primary collision with the hood panel 1, the hood panel 1 indirectly collides with another rigid body part 9 due to deformation. When the secondary collision occurs, a large acceleration is generated in the pedestrian's head 10.

  In addition, since the hood panel 1 made of fiber reinforced plastic has a characteristic of high rigidity, as shown in FIG. 4, high acceleration is likely to occur in both the first peak and the second peak as compared to the metal hood panel. On the other hand, in the metal hood panel, the first peak is low, and the second peak is often lowered because the metal food panel proceeds to the plastic region as the deformation progresses.

  Since the HIC value is obtained by integrating the time-acceleration diagram as shown in the equation (1), the integrated value is often large in a history where two peaks occur as shown in FIG. It becomes difficult to satisfy the HIC value.

  FIG. 5 shows an optimal acceleration waveform for reducing the HIC value proposed by Okamoto as one method for realizing the required HIC value (Okamoto (Concept of good design for reducible reduction in headinury, 14th ESV conference, 1994)). What Okamoto proposes is that it is necessary to make the first peak as high as possible and the subsequent second peak as low as possible. Then, collision energy can be absorbed efficiently, and as a result, the HIC value can be reduced.

  Based on this theory, the operation of the hood panel 1 in the present invention will be described.

  FIG. 6 and FIG. 7 show the front structure of the vehicle body on which the hood panel 1 according to the present invention is installed, and show the behavior when the pedestrian's head 10 collides. FIG. 8 is a diagram showing the relationship between the time when the pedestrian's head 10 collides with the hood panel 1 according to the present invention and the acceleration generated on the pedestrian's head 10.

  As shown in FIG. 6, when the pedestrian's head 10 collides with the outer panel 2, the hood panel 1 is deformed. As described above, since the fiber reinforced plastic hood panel 1 has the characteristic of high rigidity, the first peak can be raised to a higher value than the metal hood panel, and the head collision energy can be efficiently absorbed. .

  When the hood panel 1 is further deformed, the inner panel 3 collides with a rigid part 9 such as an engine as shown in FIG. When this collision occurs (point P1 in FIG. 8), the adhesion of the low-strength bonding portion 8 is peeled off, and the bonding between the outer panel 2 and the inner panel 3 is partially released. As a result, when proceeding from the point P1 in FIG. 8, the acceleration decreases with the point P2 as the second peak, and the acceleration waveform becomes G3 indicated by a one-dot chain line.

  For this reason, compared with the 2nd peak P3 when not providing the low intensity | strength adhesion part 8 as shown in FIG. 9, in this embodiment, the raise of the acceleration of a secondary collision can be relieve | moderated significantly.

  Therefore, in this embodiment, the high first peak, which is a characteristic of the fiber reinforced plastic hood panel 1, is maintained, the energy absorption amount is secured, and the low-strength adhesive portion 8 is provided, thereby providing an impact (second 2 peaks) can be relaxed.

Next, the adhesive strength of the low strength adhesive portion 8 will be described.
As described above, the adhesive strength of the low-strength adhesive portion 8 needs to have such an adhesive strength that the adhesive with the outer panel 2 is peeled off when the inner panel 3 collides with a rigid part 9 such as an engine. is there. In the present invention, in order to adjust the adhesive strength of the low-strength adhesive portion 8, as shown in FIGS. 11 to 15, the application thickness of the adhesive, the adhesive area, the type of adhesive, and the surface treatment of the adherend For example, the following various configurations can be adopted for the bonding portion 7.

  FIG. 11 is a cross-sectional view showing the low-strength adhesive portion 8 of the hood panel 1 according to one embodiment of the present invention. In the present embodiment, the low-strength adhesive portion 8 is formed by changing the coating thickness of the adhesive 11. Specifically, the adhesive 11 of the low strength adhesive portion 8 is formed by being applied thicker than the adhesive 6 of the adhesive portion 7.

  For example, Japanese Patent Publication No. 7-51318 discloses that a method for adjusting the adhesive strength of an adhesive is realized by changing the coating thickness. If this method is used, the low-strength adhesive portion 8 can be provided by increasing the coating thickness of the low-strength adhesive portion 8 over the other adhesive portions 7.

  In the food panel 1 of the present invention, from the viewpoint of cost and weight, the thickness of the adhesive 6 applied to the adhesive portion 7 is preferably in the range of 0.1 mm to 1.0 mm. There is a risk that the amount of use will be excessive. On the other hand, the thickness of the adhesive 11 applied to the low-strength adhesive portion 8 is based on the thickness of the adhesive 6 applied to the adhesive portion 7 when the inner panel 3 collides with a rigid part 9 such as an engine. It can adjust suitably so that it may become the adhesive strength from which adhesion | attachment with the outer panel 2 peels.

Further, as shown in FIGS. 12 and 13, it is possible to adjust the adhesive strength by providing a step or an inclination in the low-strength adhesive portion 8.
If a step or inclination is provided, the direction and time at which the adhesive is peeled can be appropriately controlled as necessary.
Being able to control these means that the degree of freedom of design becomes high, and is effective in designing a hood, particularly for a pedestrian head protection performance.
For example, as described above, the direction can be controlled by using the fact that the adhesive strength is low on the thick side and low on the thin side, as described above, and can start peeling from the thick side and progress toward the thin side.
In addition, since the change (distribution) of the thickness is correlated with the change (distribution) of the adhesive strength, the time of peeling progress can be controlled by giving the change to the thickness. It is also possible to stop the progress of peeling along the way.
These steps and the shape of the slope can be appropriately adjusted together with the adhesive thickness so that the required performance can be expressed based on the design.
Moreover, this form is preferable also from the point on manufacture of the food panel 1. FIG. For example, in the bonding process at the time of manufacturing the food panel 1, when the adhesive 11 is relatively low in viscosity and cannot maintain the thickness (shape), it is preferable in that the coating thickness can be controlled on the inner panel 3 side.

  Further, the low-strength adhesive portion 8 can be formed by changing the application area of the adhesive 11. Specifically, as shown in FIG. 14, the application width of the adhesive 11 in the low-strength adhesive portion 8 (referring to the length in the left-right direction of the adhesive 11 in FIG. 14) is equal to the adhesive 6 in the adhesive portion 7. It is preferably formed by being applied shorter than the application width.

  The fact that the adhesive strength of an adhesive can be adjusted by changing the coating area is disclosed in, for example, “Adhesion Encyclopedia” (Ichiro Shibazaki, published by Kobunshi Shuppankai, 1985, non-patent document).

  According to this document, as shown in FIG. 16, the relationship between the application width of the adhesive (shown as the overlap length in the figure) and the breaking load is disclosed. According to this figure, if the width at which the members are joined (that is, the portion corresponding to the adhesive application area) is reduced, the adhesive strength decreases, and even if the width is increased beyond a certain width (that is, the adhesive application area). This shows that the adhesive strength is almost constant (even if becomes larger). This is because the area near the edge of the adhesive bears the load, and the central area has a small contribution to the adhesive strength. For this reason, even if the coating width is increased beyond a certain width, only the central area with a small contribution is expanded, and the adhesive strength does not change greatly. However, as the coating width becomes narrower, the central area disappears, and the area bearing the load becomes smaller, so that the adhesive strength of the entire bonded portion can be lowered.

  From this knowledge, the low-strength adhesive portion 8 can be provided by making the application width of the low-strength adhesive portion 8 shorter than the other adhesive portions 7. The width of the adhesive 11 applied to the low-strength adhesive portion 8 can be appropriately adjusted so that the adhesive 11 is peeled off when the inner panel 3 collides with a rigid component 9 such as an engine.

  In FIG. 14, the application area is described as the width of the inner panel 3 (length in the left-right direction), but the present invention is not limited to this direction, and for example, the application area in the longitudinal direction (vertical direction in the figure) is changed. It is also possible to combine the width and the longitudinal direction.

  In addition, when a sufficient application area cannot be secured due to restrictions such as the location where the inner panel 3 is applied and the gap with the rigid part 9 such as the engine, the adhesive is relatively bonded by applying unevenness to the adhesive application surface. It is also possible to provide a difference in the application area between the portion 7 and the low strength adhesive portion 8.

  When these methods described above are used, the same type of adhesive can be applied to the adhesive portion 7 and the low-strength adhesive portion 8, so that work mistakes such as misadhesion of adhesive during assembly can be prevented, and work time can be reduced. It is possible to suppress the increase in

  Further, FIG. 15 is a cross-sectional view showing a low-strength adhesive portion 8 used in a hood panel 1 according to another embodiment of the present invention. In the present embodiment, the low-strength adhesive portion 8 is formed by changing the type of the adhesive 11. Specifically, the low-strength adhesive portion 8 is formed by applying an adhesive 11 ′ having lower strength than the adhesive 6 of the other adhesive portion 7.

  For example, a urethane-based adhesive (for example, manufactured by Etec Co., Ltd., Mighty Grip 5000, shear strength 17.7 MPa) is used for the low-strength bonding portion 8, and an epoxy-based adhesive (for example, manufactured by Toray Industries, Inc.) is used for the bonding portion 7. , Chemit TE2220, shear strength 45 MPa), it is possible to easily peel off the low-strength adhesive portion 8 by utilizing the difference in the shear strength of the adhesive.

  As an index for selecting an adhesive to be used for the low-strength adhesive portion 8, in addition to the shear strength of the adhesive, it is also possible to use the peel strength. However, in general, the peel strength of the adhesive is often lower than the shear strength, and therefore, the design is often designed so that the peel load is not input to the bonded portion in the design stage. Therefore, when the peel strength is used, it is necessary to input the peel load at the time of design or to check whether the load level is sufficient to cause breakage.

  In addition to this, the urethane adhesive is applied only to a part of the low-strength adhesive part 8, and the same epoxy adhesive as the adhesive part 7 is applied to the remaining part, or another adhesive is combined. It is also a preferable aspect to apply. A plurality of adhesive application locations, application ratios, and the like can be selected as appropriate depending on constraints such as a location where the inner panel 3 is attached and a gap with the rigid part 9 such as an engine.

  Furthermore, it is also possible to perform a surface treatment on either or both of the bonded portion 7 of the outer panel 2 or the inner panel 3, the bonded surface (not shown) of the outer panel 2 to which the bonded portion 7 is bonded. Surface roughening is performed on either the surface to be bonded of the outer panel 2 or the bonded portion 7 of the inner panel 3, or both by, for example, cleaning treatment with water or detergent, degreasing treatment with a solvent, sandpaper or sandblasting. Adhesion strength can be increased by applying chemical treatment such as edging or modification with treatment or chemicals. For this reason, the adhesive can be easily peeled off if the surface of the bonded portion to be the low strength bonded portion 8 or the bonded surface of the outer panel 2 is not subjected to surface treatment.

  In the present invention, these methods described above can be combined as appropriate. In order to reliably absorb the impact energy, it is preferable to appropriately select the application thickness, the application area, the type of the adhesive, and the like so that the adhesive can be reliably peeled off.

  An object of the present invention is to achieve the weight reduction while reliably absorbing the impact energy and maintaining the high rigidity performance of the fiber reinforced plastic food panel. Therefore, the inner panel 3 is preferably reduced in number and size as much as possible. Further, in recent years, the number of parts of the rigid parts 9 such as the engine inside the automobile has increased, and it has become impossible to ensure a sufficient space in the hood panel 1.

  In such a situation, the shape of the inner panel of the fiber reinforced plastic food panel is that the fiber reinforced plastic has characteristics of higher rigidity / higher strength than metal, and therefore the shape of the inner panel 3 is as shown in FIG. A frame-like shape in which the beam extends over the peripheral edge of the outer panel 2 is preferable. However, it is also possible to arrange the beam at a place other than the outer peripheral edge portion in the case where the rigidity is insufficient locally or from the viewpoint of attachment of other parts, interference with other parts, and the like. For example, the shape of the inner panel 3 can be selected as needed, such as a square shape shown in FIG. 17 or a V shape shown in FIG.

  Next, the site | part which provides the low intensity | strength adhesion part 8 is demonstrated.

  The low-strength adhesive portion 8 is provided at the front center of the hood panel 1 in FIG. 1 or FIG. 2, but the present invention is not limited to this position. As shown in FIG. 10, when the hood panel 1 is mounted, the location where the low-strength adhesive portion 8 is provided is a distance WAD (WrapAround) from the ground directly below the front edge of the vehicle body measured along the vehicle body contour of the vehicle. It is preferable that the distance is within a range of 1000 mm to 2100 mm. These areas are areas where the pedestrian's head 10 collides with a high percentage.

  In FIG. 1, only one low-strength adhesive portion 8 is provided, but the location where the inner panel 3 collides with a rigid part 9 such as an engine, particularly where the clearance between the inner panel 3 and the rigid part 9 is small. It is preferable to provide a plurality of low-strength adhesive portions 8.

  The reason for this is that, at the point where the clearance is small, after the first peak, the speed of the pedestrian's head 10 is still high enough to collide with the rigid part 9 when the impact energy is not sufficiently absorbed. This is because it occurs greatly and the HIC value increases. Providing a plurality of low-strength adhesive portions 8 at such locations is more preferable in that the second peak can be reduced and the impact caused by the secondary collision can be reduced.

  In particular, when the shape of the inner panel 3 as shown in FIGS. 17 and 18 is adopted, the engine is often arranged in the center of the engine room, and the beam 12 of the inner panel 3 is arranged immediately above the engine. In many cases, a place where the clearance with the rigid part 9 such as an engine becomes particularly small occurs. Even in such a case, the low-strength bonding portion 8 is effective.

  Next, the configuration of the outer panel 2 and the inner panel 3 will be described.

  In the present invention, each of the outer panel 2 and the inner panel 3 may have a sandwich structure in which a core material is interposed between skin plates made of fiber reinforced plastic, in addition to a single plate structure of fiber reinforced plastic. As a core material in the case of adopting a sandwich structure, an elastic body, a foam material, and a honeycomb material can be used, and a foam material is particularly preferable for reducing the weight. As the material of the foam material, for example, a foam material of a polymer material such as polyurethane, acrylic, polystyrene, polyimide, vinyl chloride, or phenol can be used. As the honeycomb material, for example, aluminum alloy, paper, aramid paper or the like can be used.

  In the present invention, the fiber-reinforced plastic refers to a plastic obtained by impregnating a matrix resin into a reinforcing fiber layer and curing it. Examples of the reinforcing fibers constituting the reinforcing fiber layer include reinforcing fibers made of inorganic fibers such as carbon fibers and glass fibers, and organic fibers such as Kevlar fibers, polyethylene fibers, and polyamide fibers. From the viewpoint of easy control of surface rigidity, it is particularly preferable to use carbon fibers as reinforcing fibers. Here, “surface rigidity” refers to rigidity for maintaining an initial predetermined surface shape.

  Examples of matrix resins used for fiber reinforced plastics include thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, and acrylic resins, polycarbonate resins, polyethylene resins, and polypropylene resins. Polyamide resins, polyolefin resins, dicyclopentadiene resins, polyurethane resins, polybutylene terephthalate resins, polyacetal resins, ABS resins, and modified resins obtained by alloying these resins can also be used.

  The automobile food panel of the present invention is produced by a fiber reinforced plastic manufacturing method such as a hand lay-up method, an autoclave method, an RTM (Resin Transfer Molding) method, a VaRTM (Vacuum Assisted Resin Transfer Molding) method, an SCRIMP method, or an SPRINT method. It is possible to manufacture.

  For example, in the RTM method, a dry reinforcing fiber layer that is not impregnated with a matrix resin in a cavity formed by a male mold and a female mold or a preform (in a state where the reinforcing fiber layer is deformed along the mold shape). In this molding method, a fiber base material such as a reinforced fiber layer laminated with adhesive resin, stitch yarn, or the like is bonded and the shape is fixed, and the matrix resin is pressurized and injected therein. Moreover, VaRTM method arrange | positions the fiber base material similar to the above to the cavity formed, for example by either male type | mold or female type | mold, and bag material (for example, what has flexibility, such as a nylon film, a silicone rubber), In this molding method, the inside of the cavity is decompressed, and the matrix resin is injected into the cavity at a pressure difference from the atmospheric pressure. Here, as a fiber base material, the part which should be an outer thick plate part is formed thicker by increasing the number of laminated reinforcing fiber layers than other parts. These RTM, VaRTM, and SCRIMP injection molding methods have shorter molding cycles and better mass productivity than other fiber-reinforced plastic manufacturing methods, and the quality of the preform placement is constant. From the viewpoints of stability and high degree of freedom in shape, it is excellent as a molding method for automobile members made of fiber reinforced plastic, and it is preferable to mold these molding methods in the automobile food panel of the present invention.

  Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention can be applied not only to a hood panel of a light vehicle but also to a vehicle type in which the hood panel is almost erected such as a truck.

1 is a schematic plan view of a hood panel according to an embodiment of the fiber reinforced plastic hood panel of the present invention. 1 is an exploded schematic view of a hood panel according to an embodiment of the fiber-reinforced plastic hood panel of the present invention. It is an AA arrow line view of the food panel concerning one embodiment of the fiber reinforced plastic food panel of the present invention. It is a typical figure showing the time calendar of the head generation acceleration when the head of a pedestrian collides. It is a typical figure showing the time calendar of the optimal head generation acceleration when a pedestrian's head collides. It is operation | movement explanatory drawing in the fiber reinforced plastic food panel concerning one Embodiment of this invention. It is operation | movement explanatory drawing in the fiber reinforced plastic food panel concerning one Embodiment of this invention. It is the typical figure showing the time calendar of the head generation acceleration at the time of the pedestrian's head colliding in the fiber reinforced plastic food panel concerning one embodiment of the present invention. It is operation | movement explanatory drawing in the fiber reinforced plastic food panel concerning one Embodiment of this invention. It is a figure showing distance WAD from the ground directly under the vehicle body front edge measured along the vehicle body outline of a motor vehicle. It is the schematic which shows an example concerning one embodiment of the food panel made from fiber reinforced plastics of this invention. It is the schematic which shows an example concerning one embodiment of the food panel made from fiber reinforced plastics of this invention. It is the schematic which shows an example concerning one embodiment of the food panel made from fiber reinforced plastics of this invention. It is the schematic which shows an example concerning one embodiment of the food panel made from fiber reinforced plastics of this invention. It is the schematic which shows an example concerning one embodiment of the food panel made from fiber reinforced plastics of this invention. It is a typical figure which shows the relationship between adhesion length and a shear fracture load. It is a schematic plan view which shows the case where the shape of the inner panel concerning the food panel made from fiber reinforced plastics of this invention is a square shape. It is a schematic plan view which shows the case where the shape of the inner panel concerning the fiber reinforced plastic food panel of this invention is V shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hood panel 2 Outer panel 3 Inner panel 4 Hood lock striker 5 Hinge 6 Adhesive 7 Adhesive part 8 Low-strength adhesive part 9 Rigid part 10 Pedestrian's head 11, 11 'Adhesive 12 Beam

Claims (7)

  An automotive hood panel comprising an outer panel made of fiber reinforced plastic forming an outer surface and an inner panel made of fiber reinforced plastic joined to the outer panel, wherein the inner panel is bonded to the outer panel And a part of the adhesive part is a low-strength adhesive part having lower adhesive strength than that of the other adhesive part.   The automobile food panel according to claim 1, wherein the low-strength adhesive portion is formed by changing an application thickness of the adhesive.   The automobile food panel according to claim 1, wherein the low-strength adhesive portion is formed by providing a step or / and an inclination in the adhesive portion.   The automobile food panel according to claim 1, wherein the low-strength adhesive portion is formed by changing an adhesive application area of the adhesive portion.   The said low-strength adhesion part is a food panel for motor vehicles in any one of Claims 1-4 formed by changing the kind of adhesive agent.   The hood panel for automobiles according to any one of claims 1 to 5, wherein a surface treatment is applied to the bonded portion of the inner panel and / or the bonded surface of the outer panel to which the bonded portion is bonded.   The automobile food panel according to any one of claims 1 to 6, wherein at least a part of the reinforcing fibers used in the fiber-reinforced plastic is a carbon fiber.

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